JP6684185B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a semiconductor device in which a chip-shaped component such as a semiconductor chip or a semiconductor package including a semiconductor chip is bonded to an adherend such as a substrate or an electrode using a dispersion solution of metal fine particles, and a method for manufacturing the same. Regarding

  In a sintered body formed by sintering a dispersion solution of metal fine particles, the stress concentrates immediately below the chip-shaped component due to the difference in thermal expansion. For this reason, if the hardness of the region directly below the chip-shaped component is softer than the region away from the chip-shaped component, the region directly below this chip-shaped component may preferentially deform and break. .

  On the other hand, Japanese Patent Application Laid-Open No. 2004-242242 describes that an additive element such as Sb is added to lead-free solder to harden the solder only on the surface portion. However, the technique disclosed in Patent Document 1 aims to suppress the progress of cracks by hardening the surface of the solder fillet, and to improve the bondability between the chip-shaped component and the adherend. It wasn't intended.

JP, 2014-138065, A

  However, when the chip-shaped component and the adherend are bonded using the dispersion solution of the metal fine particles, there is a problem that breakage occurs in the region directly below the chip-shaped component due to the difference in thermal expansion directly below the chip-shaped component. . Particularly in a semiconductor chip that generates a large amount of heat such as a power semiconductor, a large stress is generated at the interface between the semiconductor chip and the bonding material due to the difference in thermal expansion coefficient. Therefore, breakage often occurs at the interface between the semiconductor chip and the bonding material, which is a cause of impairing reliability.

  Therefore, an object of the present invention is to provide a semiconductor device capable of improving the reliability of connection between a chip-shaped component and an adherend and a method for manufacturing the same.

  In order to solve the above-mentioned problems, a semiconductor device of the present invention is a semiconductor device having a bonding layer between a chip-shaped component and an adherend, and is directed toward the adherend based on the interface between the chip-shaped component and the bonding layer. The hardness D1 of the bonding layer in the range including the thickness of 30 μm is larger than the hardness D2 of the bonding layer in the range of including the thickness of 30 μm toward the chip-shaped component on the basis of the interface between the adherend and the bonding layer. Is.

  That is, when the strength of the bonding layer between the chip-shaped component and the adherend is constant in the depth direction, the degree of deformation with respect to stress is the same, so the degree of deformation due to stress generated from the difference in thermal expansion coefficient is The interface is the largest. On the other hand, if the stress can be propagated to the adherend side and the portion distant from the interface can be deformed, the stress can be received by the entire bonding layer, and the degree of stress concentration can be reduced. Therefore, the strength of the bonding material near the chip interface is increased to make it difficult to deform due to stress, and the stress is propagated to the part away from the interface, and the part away from the interface is deformed by lowering the strength. To With such a strength distribution of the bonding material, stress can be received as a whole bonding layer, so that stress concentration at the chip interface is reduced, and reliability of bonding between the chip-shaped component and the adherend can be improved. it can.

  In a bonding material using copper nanoparticles, a mixture of copper nanoparticles and an activator is heated and sintered. Therefore, the state of the sintered body can be changed depending on the mixing ratio of the copper nanoparticles and the activator. At this time, the larger the amount of the activator, the easier the sintering proceeds, and the mechanical strength increases. On the contrary, the smaller the amount of the activator, the more difficult it is for the sintering to proceed, and the relatively large mechanical strength. By utilizing this property and forming a portion having a large amount of activator and a portion having a small amount of activator in the bonding layer, a strength distribution can be formed in the bonding layer. Therefore, a desired structure can be formed by increasing the amount of the activator near the interface between the chip-shaped component and the bonding layer and decreasing the amount of the activator near the interface between the bonding layer and the adherend.

  The bonding layer using copper nanoparticles can be supplied by a paste in which copper nanoparticles and an activator are mixed. However, the paste contains an activator in an amount larger than that required during sintering in order to ensure fluidity. Therefore, it is necessary to evaporate the excess solvent by a drying process after printing. As a result, after the drying treatment, the amount of solvent on the surface is small, and the amount of solvent increases toward the inside. In consideration of such conditions, the portion to be bonded to the adherend becomes the surface of the paste, that is, if the chip-shaped component is printed, the activator remains on the chip-shaped component side more than the surface, It is possible to form a bonding layer having high strength on the chip-shaped component side and low strength on the adherend side.

  According to the semiconductor device and the method for manufacturing the same of the present invention, the reliability of the connection between the chip-shaped component and the adherend can be improved.

It is a sectional view of the important section of a semiconductor device.

  Next, a semiconductor device and a method for manufacturing the same according to one embodiment of the present invention will be described with reference to the drawings. The embodiments described below are preferred specific examples of the semiconductor device and the manufacturing method thereof according to the present invention, and may have various technically preferable limitations. However, the technical scope of the present invention is Unless otherwise specified, the present invention is not limited to these embodiments. Further, the constituent elements in the embodiments described below can be appropriately replaced with existing constituent elements and the like, and various variations including a combination with other existing constituent elements are possible. Therefore, the description of the embodiments below does not limit the contents of the invention described in the claims.

  Next, embodiments of the present invention will be described in detail below. FIG. 1 shows an example of a semiconductor device. As shown in FIG. 1, the semiconductor device 1 has a bonding layer 4 between a semiconductor chip 2 as a chip-shaped component and a substrate 3 as an adherend. The chip-shaped component may be the semiconductor chip 2 or a semiconductor package including the semiconductor chip 2 or the like. Further, the adherend may be other than the substrate 3, such as an electrode.

  In the bonding layer 4, the hardness D1 of the upper bonding layer 4a within the range including the thickness H1 = 30 μm toward the substrate 3 with reference to the interface with the semiconductor chip 2 is a semiconductor with the interface between the substrate 3 and the bonding layer 4 as reference. The hardness D2 is greater than the hardness D2 of the bonding layer 4 within the range including the thickness H2 toward the chip 2 = 30 μm (D1> D2).

  The hardness D1 and the hardness D2 are nanoindenter hardness, and are preferably in the range of 0.50 ≦ D2 / D1 ≦ 0.88. Note that details regarding this numerical limitation will be described later.

  The bonding layer 4 is a dispersion solution of metal particles (P) containing copper nanoparticles (P1) having an average primary particle diameter of 2 nm to 500 nm and metal particles containing an organic dispersion medium (S) containing a trivalent alcohol (A1a). And a metal porous body formed by heating and sintering. At this time, it is preferable that the metal particles (P) include metal fine particles (P2), and the metal fine particles (P2) include copper fine particles. Further, the bonding layer 4 has a concentration C1 of the copper nanoparticles (P1) of the upper bonding layer 4a within a range including the thickness H1 = 30 μm toward the substrate 3 with the interface between the semiconductor chip 2 and the bonding layer 4 as a reference, It is lower than the concentration C2 of the copper nanoparticles (P1) of the lower bonding layer 4b within a range including the thickness H2 = 30 μm toward the semiconductor chip 2 on the basis of the interface between the substrate 3 and the bonding layer 4, and 0.67. It is desirable to be in the range of ≦ C1 / C2 ≦ 0.88. The details regarding this material limitation will be described later.

  In such a basic configuration of the semiconductor device 1, the hardness of the upper bonding layer 4a on the heat generating side (usually the semiconductor chip side) of the semiconductor device 1 is increased to increase the strength, and the lower bonding layer 4b on the opposite side is hardened. By lowering the temperature to propagate the stress generated from the thermal strain, the reliability of the connection of the semiconductor device 1 can be improved.

  In particular, it has been found that the highly reliable semiconductor device 1 can be obtained by printing the dispersion solution of the metal fine particles on the side where heat is generated, predrying and sintering under pressure. At this time, it is preferable that the hardness D2 of the lower bonding layer 4b having a low hardness be 0.5 to 0.88 times, based on the hardness D1 of the upper bonding layer 4a having a high hardness. If the hardness D2 exceeds 0.88 times, thermal strain does not propagate and reliability may be reduced. If the hardness D2 is less than 0.5 times, the strength of the lower bonding layer 4b may be too low to perform reliable bonding.

[1] Dispersion solution of metal particles (1) Metal particles (P)
The metal particles (P) need to have sinterability. In addition to the case where the metal particles (P) are composed of only the copper nanoparticles (P1) having an average primary particle diameter of 2 to 500 nm, in addition to the copper nanoparticles (P1), the average primary particle diameter is 0.5 μm. You may comprise as mixed particles which mixed the metal fine particles (P2) of more than 50 micrometers or less.

(A) Copper nanoparticles (P1)
The copper nanoparticles (P1) are not particularly limited as long as they are copper fine particles having an average primary particle diameter of 2 nm to 500 nm. If the average particle diameter of the primary particles of the copper nanoparticles (P1) is less than 2 nm, it is difficult to manufacture. On the other hand, if the average particle diameter of the primary particles is 500 nm or more, the melting point does not decrease during sintering and This is because the sex deteriorates. Inevitable impurities in the copper nanoparticles include boron (B), calcium (Ca), iron (Fe), potassium (K), sodium (Na), nickel (Ni), lead (Pb), strontium (Sr), Zinc (Zn), chromium (Cr), magnesium (Mg), silicon (Si), and phosphorus (P) may be contained at about 30 ppm or less each.

  Here, the "primary particle diameter" means the diameter of the primary particles of the individual metal particles constituting the secondary particles. The primary particle diameter can be measured by using an electron microscope (SEM (scanning electron microscope)). In the present invention, SEM (manufactured by Hitachi High-Technologies Corporation, device name "SU8020") was used to observe at an accelerating voltage of 3 kV and a magnification of 200,000 to obtain a SEM image. Then, arbitrary 20 particles were selected from the image, the particle diameter was measured, and the average thereof was calculated to obtain the average particle diameter. The "average primary particle size" means the number average particle size of primary particles.

(B) Metal fine particles (P2)
The metal fine particles (P2) have an average particle size of primary particles of 0.5 μm to 50 μm, and are used when the metal particles (P) are constituted as mixed particles with the copper nanoparticles (P1). The metal fine particles (P2) are not particularly limited, but gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), tungsten (W), nickel (Ni), iron ( Fe, cobalt (Co), tantalum (Ta), bismuth (Bi), lead (Pb), indium (In), tin (Sn), zinc (Zn), titanium (Ti), and aluminum (Al). One kind or two or more kinds of fine particles can be used, and copper is particularly preferable.

  When copper nanoparticles (P1) having an average primary particle diameter of 2 nm to 500 nm and metal fine particles (P2) having an average primary particle diameter of 0.5 μm or more and 50 μm or less coexist, copper nanoparticles (P2) are present between the metal nanoparticles (P2). P1) intervenes in a moderately dispersed state and can effectively suppress the free movement of the copper nanoparticles (P1) during the heat treatment, and thus the dispersibility and stability of the copper nanoparticles (P1) described above. As a result, it becomes possible to form a porous body having a more uniform particle size and pores by heating and firing (sintering).

  The average primary particle diameter of the metal fine particles (P2) is preferably more than 0.5 μm and 50 μm or less. If the average primary particle diameter of the metal fine particles (P2) is 0.5 μm or less, the effect of adding the metal fine particles (P2) will not be exhibited, and if it exceeds 50 μm, firing may be difficult. The "average primary particle diameter" is defined as the particle diameter with a cumulative frequency of 50% measured by a laser diffraction type particle size distribution meter.

(2) Organic dispersion medium (S)
The dispersion solution of the metal particles (P) of the present invention is formed by dispersing the metal particles (P) in the organic dispersion medium (S). The organic dispersion medium (S) contains trivalent alcohol which is an activator. In addition, it is preferable to include one or more polyhydric alcohols (A1) having two or more hydroxyl groups in the molecule, and as the other organic solvent, a compound (A2) having an amide group and an amine compound. (A3), a low boiling point organic compound (A4) and the like may be contained.

(A) Trihydric alcohol Trihydric alcohol includes glycerin (glycerol), 1,1,1-trishydroxymethylethane, 1,2,6-hexanetriol, 1,2,3-hexanetriol, 1, One or more selected from 2,4-butanetriol can be contained, and glycerin is particularly preferable.

(A) Polyhydric alcohol (A1)
As the polyhydric alcohol (A1) other than the trihydric alcohol, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanedioyl having two or more hydroxyl groups in the molecule. 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-butene-1,4-diol, 2,3-butanediol, pentanediol, hexanediole. , Octandiol, threitol, erythritol, pentaerythritol, pentitol, 1-propanol, 2-propanol, 2-butanol, 2-methyl 2-propanol, xylitol, ribitol, arabitol, hexitol. Le, mannitol, sorbitol, dulcitol, glycerinaldehyde, dioxyacetone, threose, erythrough , Erythrose, arabinose, ribose, ribulose, xylose, xylulose, lyxose, glucose, fructose, mannose, idose, sorbose, growth, talose, tagatose, galactose, allose, altrose, lactose, isomaltose, One or more selected from glucoheptose, heptose, maltotriose, lactulose, and trehalose can be mentioned.

  By containing the polyhydric alcohol (A1) in the organic dispersion medium (S), since it has reducibility, the surface of the metal fine particles (P) is reduced, and the polyhydric alcohol (A1) is converted by further heat treatment. When the metal particles (P) are continuously evaporated and reduced / calcined in an atmosphere in which the liquid and vapor are present, the sintering of the metal particles (P) can be promoted. Considering the sinterability of the heat-bonding material (M), which is formed by using the dispersion solution of the metal particles (P) and is in the state before the heating / sintering of the bonding layer, the polyhydric alcohol (A1) is an organic compound. The dispersion medium (S) preferably contains 40% by mass or more.

(B) A compound having an amide group (A2)
Examples of the compound (A2) having an amide group include N-methylacetamide, N-methylformamide, N-methylpropanamide, formamide, N, N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N, N-dimethylformamide, 1-methyl-2-pyrrolidone, hexamethylphosphoric triamide, 2-pyrrolidone, alkyl-2-pyrrolidone, ε-caprolactam, and acetamide, polyvinylpyrrolidone, polyacrylamide, and N-vinyl-2- One or more selected from pyrrolidone can be exemplified. The compound (A2) having an amide group is used as an organic modified product that covers the surface of metal particles. The compound (A2) having an amide group is preferably blended so as to be 10 to 80 mass% in the organic dispersion medium (S).

(C) Amine compound (A3)
The amine compound (A3) is selected from an aliphatic primary amine, an aliphatic secondary amine, an aliphatic tertiary amine, an aliphatic unsaturated amine, an alicyclic amine, an aromatic amine, and an alkanolamine. One or more amine compounds may be mentioned, and specific examples thereof include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-propylamine. , N-butylamine, di-n-butylamine, tri-n-butylamine, t-propylamine, t-butylamine, ethylenediamine, propylenediamine, tetramethylenediamine, tetramethylpropylenediamine, pentamethyldiethylenetriamine, mono-n-octylamine , Mono-2 Etchi Hexylamine, di-n-octylamine, di-2ethylhexylamine, tri-n-octylamine, tri-2ethylhexylamine, triisobutylamine, trihexylamine, triisooctylamine, triisononylamine, triphenylamine , Dimethyl coconut amine, dimethyl octyl amine, dimethyl decyl amine, dimethyl lauryl amine, dimethyl myristyl amine, dimethyl palmityl amine, dimethyl stearyl amine, dimethyl behenyl amine, dilauryl monomethyl amine, diisopropyl ethyl amine, methanol amine, dimethanol amine, Trimethanolamine, ethanolamine, diethanolamine, triethanolamine, propanolamine, isopropanolamine, diisopropanol Ruamine, triisopropanolamine, butanolamine, N-methylethanolamine, N-methyldiethanolamine, N, N-dimethylethanolamine, N-ethylethanolamine, N-ethyldiethanolamine, N, N-diethylethanolamine, Nn -Butyl ethanolamine, Nn-butyl diethanol amine, and 1 type (s) or 2 or more types selected from 2- (2-aminoethoxy) ethanol can be mentioned. The amine compound (A3) is preferably mixed in the organic dispersion medium (S) so as to be 0.3 to 30% by mass.

(D) Low boiling point organic compound (A4)
The low boiling point organic compound (A4) has a boiling point of 60 to 120 ° C. under normal pressure (boiling point refers to a boiling point under normal pressure; the same applies hereinafter), and is a relatively low boiling point organic compound. The low boiling point organic compound (A4) is preferably one or more selected from alcohols, ethers and ketones having one hydroxyl group in the molecule.

  As the alcohol having one hydroxyl group in the molecule, methanol (64.7 ° C.), ethanol (78.0 ° C.), 1-propanol (97.15 ° C.), 2-propanol (82.4 ° C.), One or two or more kinds selected from 2-butanol (100 ° C.) and 2-methyl 2-propanol (83 ° C.) can be exemplified. Examples of the ether include diethyl ether (35 ° C), methylpropyl ether (31 ° C), dipropyl ether (89 ° C), diisopropyl ether (68 ° C), methyl-t-butyl ether (55.3 ° C), t-amyl. One or more selected from methyl ether (85 ° C.), divinyl ether (28.5 ° C.), ethyl vinyl ether (36 ° C.) and allyl ether (94 ° C.) can be exemplified. Moreover, as said ketone, 1 type (s) or 2 or more types selected from acetone (56.5 degreeC), methyl ethyl ketone (79.5 degreeC), and diethyl ketone (100 degreeC) can be illustrated.

  By including the low boiling point organic compound (A4) in the organic dispersion medium (S), it is possible to adjust the viscosity of the organic dispersion medium (S) and improve the accuracy of pattern formation. The content of the low boiling point organic compound (A4) in the organic dispersion medium (S) is preferably 1 to 30% by mass.

[2] Method for Manufacturing Bonded Structure Next, an example of a method for manufacturing a bonded structure suitable for manufacturing using the dispersion solution of metal particles according to the present invention will be described below. A method for producing a bonded structure according to the present invention includes a first step of using the above-mentioned dispersed solution of metal particles and disposing the dispersed solution of metal particles between a first adherend and a second adherend. A second step of drying the dispersion solution at 110 ° C. to obtain a heat-bonding material, and a third step of sintering the heat-bonding material. The method for manufacturing a bonded structure according to the present invention is performed, for example, by disposing a heating bonding material between the semiconductor chip 2 and the substrate 3 and then introducing this object to be processed into a device that can be pressed in vacuum. You can When the heat-bonding material is a paste-like material, the bonding structure can be manufactured by forming a bonding layer after sintering by using a coating method or a printing method on one of the surfaces to be bonded.

(1) First Step In the first step, metal particles are provided between the semiconductor chip 2 (or a chip-like component such as a semiconductor package including a semiconductor chip) and the substrate 3 (or an adherend such as an electrode). Is a step for arranging the dispersion solution of.

  The dispersion solution of the metal particles used to form the heat bonding material (M) has a stable organic dispersion medium (S) / metal particle (P) ratio (mass ratio) in consideration of patterning and sinterability. 10/90 to 70/30 is preferable to obtain the bonding force, but the ratio is determined depending on whether the sheet-shaped heat-bonded molded product (T1) or the heat-bonded paste-like material (T2) is selected. It is determined.

  When the ratio of organic dispersion medium (S) / metal particles (P) is less than 10/90, the metal particles (P) remain powdery when the heating bonding material (M) is formed. It tends to exist in and is impossible to paste. Further, if the organic dispersion medium is more than 70/30, there is no shape stability after printing, and printing tends to be impossible. The preferable range of this ratio is 20/80 to 60/40 for printing and 10/90 to 30/70 for processing into a sheet.

  The dispersion solution of metal particles can be obtained by dispersing the metal particles (P) in the organic dispersion medium (S) using a known mixer, kneader, or the like.

(2) Second Step The second step is a step of (preliminarily) drying the dispersion solution after the first step to form a heat bonding material.

  The heating bonding material (M) can be a heating bonding paste (T2) in which the metal particles (P) are dispersed in the organic dispersion medium (S). Further, as the heat bonding material (M), a patterned product made of the heat bonding material (M) can be arranged on the surface to be bonded (for example, the surface of the semiconductor chip). In this case, when the substrate 3 is placed on this patterned product and the metal particles (P) are heated in a sintering temperature range, the trivalent alcohol (A1a) reduces the surface of the copper nanoparticles (P1). It is activated and the sintering of the metal particles (P) is promoted. As a result, it becomes possible to electrically and mechanically bond the electrode and the substrate 3 as in the case of using a paste-like material containing nano-sized metal fine particles. When the heat bonding material (M) is heated and sintered, the organic dispersion medium (S) is removed by decomposition, evaporation or the like.

  In the present invention, the drying temperature was 110 ° C. The drying time is not particularly limited as long as it can be adjusted so that the copper concentration in the heat-bonding material (M) formed after drying is 65 to 95% by mass. It is preferably about 60 minutes.

(3) Third Step In the third step, the heating bonding material made of the dried paste material (T2) for heating bonding is sintered to form a bonding structure having a bonding layer for bonding adherends. It is a process.

  As a sintering method, for example, the object to be processed is sandwiched between press plates having a built-in heater, and then vacuuming is performed to sufficiently reduce the pressure. At this time, since the atmospheric pressure is applied to the absolute pressure, the gauge pressure in consideration of it is applied by hydraulic pressure or pneumatic pressure. The heating (sintering) temperature is preferably about 190 to 400 ° C., and the heating and holding time is preferably about 1 minute to 120 minutes.

  Then, if necessary, annealing treatment may be performed at a temperature of 190 to 400 ° C. for about 1 to 30 hours in the atmosphere, an inert atmosphere, or a reducing atmosphere such as hydrogen. By this annealing treatment, strain and residual stress in the bonding layer are removed, and reliability is further improved.

  According to the above-described method for manufacturing a bonded structure, the heating bonding material is sintered to form the bonding layer 4 made of a sintered body of a dispersion solution of metal particles, and the substrate 3 and the semiconductor chip 2 are bonded by the bonding layer 4. The semiconductor device (junction structure) 1 can be obtained. In this way, in the state where the substrate 3 and the heat bonding material are in contact with each other, and the heat bonding material and the semiconductor chip 2 are in contact with each other, these are heated without pressure or under pressure, so that The metal particles (P) are sintered to form a porous bonding layer, and the substrate 3 and the semiconductor chip 2 are bonded to each other.

  The thickness of the bonding layer (L) formed by this method is preferably in the range of 5 to 500 μm. This is because if the thickness is less than 5 μm, the paste thickness becomes thinner than the unevenness of the semiconductor chip (K), a part not covered with the paste occurs, and the bonding reliability tends to decrease. On the other hand, if the thickness exceeds 500 μm, the thermal resistance becomes too large, which is not preferable. Therefore, the thickness of the bonding layer (L) in the present embodiment is preferably a numerical value within the range of 5 to 500 μm.

  Embodiments of the present invention will be described in more detail based on the following examples. The present invention is not limited to these examples.

(1) Copper nanoparticles As the copper nanoparticles (P1), copper nanoparticles with an organic protective film were used.
The copper nanoparticles with an organic protective film were produced by the following procedure in accordance with the method described in the example of JP2011-074476A. First, 10 g of polyvinylpyrrolidone (PVP, number average molecular weight of about 3500), which is a polymer dispersant and is a raw material for an organic protective film, was dissolved in 1979.3 ml of distilled water to prepare an aqueous solution of copper nanoparticles (P1). 29.268 g of cupric hydroxide (Cu (OH) 2) with a particle size range of 0.1-100 μm was added. Next, the liquid temperature was adjusted to 20 ° C., 20.73 ml of an aqueous solution containing 150 mmol of sodium borohydride and 480 mmol of sodium hydroxide was added dropwise while stirring in a nitrogen gas atmosphere, and then the reduction reaction was carried out while stirring well for 45 minutes. went. The reduction reaction was completed at the time when the generation of hydrogen gas from the reaction system was completed. By the reduction reaction, an aqueous solution of copper nanoparticles (P1) in which the copper nanoparticles (P1) at least partially covered with the organic protective film (polymer dispersant) are dispersed in the aqueous solution was obtained. Then, 66 ml of chloroform as an extractant was added to this aqueous solution to precipitate the copper nanoparticles (P1), and solid-liquid separation was performed by centrifugation. After methanol was added and stirred, solid-liquid separation was performed by centrifugation. The particles were separated and washed. Then, after washing several times, copper nanoparticles (P1) with an organic protective film were obtained. The thickness of the organic protective film (F1) was 0.6 mass% when measured using a carbon / sulfur concentration analyzer as a mass ratio occupying the entire copper nanoparticles (P1). The average primary particle diameter of the copper nanoparticles (P1) was 50 nm. An SEM image was obtained by observing with an SEM (manufactured by Hitachi High-Technologies Corporation, device name “SU8020”) at an acceleration voltage of 3 kV and a magnification of 200,000 times. Then, arbitrary 20 primary particles were selected from the image to measure the particle size, and the average value calculated from the measured values of the particle sizes was taken as the average primary particle size.

(2) Preparation of Dispersion Solution of Metal Particles (P) The dispersion solution of metal particles (P) was prepared by blending copper nanoparticles (P1), metal fine particles (P2) and glycerin. Also, the copper concentration was adjusted to 60% by weight.

(3) Evaluation method Printing was performed on the semiconductor chip side with a paste thickness of 400 um, and the paste was dried in a dry atmosphere at 110 ° C so that the copper concentration was 65 to 95% or more. After that, the semiconductor chip 2 was mounted on the copper substrate 3, and pressure heating and sintering were performed under vacuum at 300 ° C. for 20 minutes at 10 MPa. After that, a thermal shock test (manufacturer: Espec model number: TSE-11-A) at −55 to 200 ° C. is performed, and it is taken out every 100 times, SAT observation of the interface is performed, and failure occurs when the peeled area exceeds 10%. And In this evaluation shown in Table 1 below, the reliability is insufficient when a failure occurs less than 700 times, for example, when an automotive inverter is considered as an application example of a semiconductor device. Therefore, 700 times or more satisfying the above conditions were evaluated as ◯, and 1000 times or more were evaluated as ⊚ as a criterion for higher reliability. In addition, the hardness of the cross section is measured so that the center of the sintered sample can be observed, and the hardness is measured at 20 points within 30 μm from the interface with a nano indenter. The average value of 15 points with 2 points of hardness deleted was obtained. Since P2 particles are not a substance derived from nanoparticles, the portion consisting of nanoparticles was selected and measured.

The cross-section was obtained by the following method.
(1) A sample is embedded in a resin, cut so that the central portion of the chip appears, and polished.
(2) After cutting a cross-section sample into a space that fits into cp (Chemical Bollicer: Ar plasma cross-section device manufacturer: JEOL model number: SM-09010), the cross-section is taken out with cp.
(3) Adjust the size of the sample so that it enters the nano indenter.
(4) Measure with a nano indenter (manufacturer: HALCYONICS MOD-1MP Plus).
(5) A Berkovich indenter (triangular pyramid indenter) was used as the indenter.
By adopting this method, the hardness of the cross section can be measured without being affected by the surface-altered layer formed during polishing.

  The copper concentration of the film after preliminary drying was measured as follows. The distribution of copper concentration in the depth direction after predrying was performed by FIB processing while cooling to -140 ° C with liquid nitrogen, and quantitative analysis of carbon and copper was performed by EDX installed in the FIB device as it was. Was calculated, and the copper concentration was calculated therefrom.

The copper concentration is the copper concentration (%) = copper weight (%) in EDX measurement / (copper weight (%) in EDX measurement + carbon weight (%) in EDX measurement)
Sought as. The amount of PVP modified around the copper particles was found to be 1 wt% or less by another measurement (measurement of total carbon amount measured in the particle state), and it does not affect this measurement. I'm confirming.

  The results are shown in Table 1 below. In the comparative example, the hardness on the semiconductor chip side is low and the reliability is poor. On the other hand, in the example, the result is that the hardness of the semiconductor chip side is high and the reliability is good.

  As described above, the semiconductor device and the method of manufacturing the same according to the present invention have the effect of improving the reliability of the connection between the chip-shaped component and the adherend, and include a semiconductor chip or a semiconductor chip. The present invention can be applied to a semiconductor device in which a chip-shaped component such as a semiconductor package is bonded to an adherend such as a substrate or an electrode using a dispersion solution of metal fine particles, and a manufacturing method thereof.

1 ... Semiconductor device 2 ... Semiconductor chip (chip-shaped component)
3 ... Substrate (adherend)
4 ... Bonding layer 4a ... Upper bonding layer (hardness D1)
4b ... Lower bonding layer (hardness D2)

Claims (6)

In a semiconductor device having a bonding layer made of a sintered body of metal particles between the chip-shaped component and the adherend,
The hardness D1 of the bonding layer within a range including the thickness of 30 μm toward the adherend with reference to the interface between the chip-shaped component and the bonding layer is based on the interface between the adherend and the bonding layer. the much larger than the hardness D2 of the bonding layer in a range including the thickness 30μm toward the chip-like component,
The semiconductor device in which the hardness D1 and the hardness D2 are nanoindenter hardness and are within a range of 0.50 ≦ D2 / D1 ≦ 0.88 . The bonding layer is formed by heating and sintering a metal particle dispersion solution containing a metal particle (P) containing copper nanoparticles (P1) having an average primary particle diameter of 2 nm to 500 nm and an organic dispersion medium (S) containing a trivalent alcohol. the semiconductor device of claim 1 in which the metal containing porous and body, and it is characterized in that to form. The semiconductor device according to claim 2 , wherein the metal particles (P) include metal fine particles (P2), and the metal fine particles (P2) include copper fine particles. In the bonding layer, the concentration C1 of the copper nanoparticles (P1) within a range including a thickness of 30 μm toward the adherend on the basis of the interface between the chip-shaped component and the bonding layer is the same as that of the adherend. The concentration is lower than the concentration C2 of the copper nanoparticles (P1) within a range including a thickness of 30 μm toward the chip-shaped component based on the interface with the bonding layer, and the range is 0.67 ≦ C1 / C2 ≦ 0.88 The semiconductor device according to claim 2 or 3 , wherein the semiconductor device is inside. The semiconductor device according to any one of claims 1 to 4 , wherein the chip-shaped component is a semiconductor chip. A method of manufacturing a semiconductor device according to any one of claims 1 to 5 , comprising:
A method for manufacturing a semiconductor device, which comprises applying a metal particle dispersion solution to one surface of a chip-shaped component, pre-drying it, and then contacting it with an adherend and performing heat bonding.

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